Conventional multilayer-deposition approaches have produced good quality periodic photonic structures, like Fabry-Perot Microcavities and distributed Bragg mirrors. More challenging is the fabrication of high quality aperiodic structures. An example of such a photonic structure is a deterministic aperiodic structure such as the one generate by a Thue-Morse sequence. This is just an example of aperiodic photonic structures and does not limit the approach we are proposing to this specific choice.
Specifically, an aperiodic structure generated by a Thue-Morse sequence is a structure obtained by the simple inflation rule σT-M: A→AB, B→BA. Very recently the authors demonstrated omnidirectional reflectivity in a passive Thue-Morse photonic structure fabricated by a standard sputtering deposition technique. It is known theoretically that aperiodic structures show fractal distribution of sharp band-edge states with resonant transmission and strong field enhancement effect.
However, despite the big potential of aperiodic structures for enhancing light-matter interactions, no such aperiodic structures have been demonstrated combining both strong light-matter interaction and light emission. In fact, the standard materials approaches used to fabricate aperiodic photonic structures are not suited to obtain strong light emission homogeneously from all the layers constituting the structures. In other words, conventional materials used to fabricate aperiodic structures do not provide efficient light emission originating homogeneously from within the photonic structure itself.
Therefore, it is desirable to develop CMOS-compatible light emitting photonic structures that can produce efficient room temperature light emission homogeneously from the inside of photonic structure. Moreover, it is desirable to develop materials that can be used to fabricate aperiodic structures that obtain strong light-matter coupling homogeneously from all the layers constituting the structures.